GASTROCOPTA, NORTH AMERICA, WEST INDIES. 55 



c 1 . Cinnamon-colored, the lip tinted. 



d. Subcolumellar nodule present. 



G. r. duplex, no. 17&. 

 d 1 . No subcolumellar nodule or callous. 



G. r. marginalba, no. 17c. 

 Form cylindric. 



c. Parietal lamella strongly bifid in a front view. 

 d. Small, length 2 to 2.45, diam. 1 mm. 

 or less. 



e. Lower palatal plica not very 

 deeply immersed; Antilles. G. 

 barbadensis and var., nos. 24, 24a. 

 e 1 . Lower palatal plica deeply im- 

 mersed; Dakota to New Mexico. 

 G. p. mcclungi, no. 18c. 

 d 1 . Larger, length 2.25 to 3, diam. 1 mm. 

 or more. 



e. Anterior end of parietal lamella 

 not conspicuous. 



/. Lip heavily calloused. 



g. A callous below colu- 

 mellar lamella. 



G. procera, no. 18. 

 g 1 . No callous below colu- 

 mellar lamella. 



G. p. riparia, no. 18a. 

 / x . Lip callous thin; an infra- 

 parietal often developed. 



G. riograndensis, no. 20. 

 e 1 . Anterior end of parietal lamella 

 distinctly projecting. 

 /. Lip-callous marginal. 



G. p. mcclungi, no. 18c. 

 jf 1 . Lip-callous further within. 



G. p. duplicata, no. 18&. 

 c 1 . Parietal lamella simpler, sinuous. 



d. Larger, strongly crested, 2.3 to 3.2 mm. 

 long, more than 1 mm. wide; Oklahoma 

 to Arizona. G. cristata, no. 19. 



